The microelectronic and optoelectronic industries have been successful in stretching the useful life of materials and methods needed for the manufacture of micro and optoelectronic devices. However, as the complexity and the desired performance of such devices increases, such mature materials and methods are becoming more and more problematic. Therefore new materials and methods are the subject of ongoing research to meet the needs of future generations of such devices as well as to improve the yield and reduce the cost of current and future devices.
Polymeric materials of various compositions have been the focus of much of the aforementioned ongoing research. However, while some such polymeric materials have been met with some successes, these materials are often limited by their physical characteristics and the processing methods they require for their use. For example, polyimide materials have been used as interlayer dielectric materials in microelectronic devices such as integrated circuits (IC's) due to their having a dielectric constant that is lower than that of silicon dioxide. Also, such polyimide materials can serve as a planarization layer for IC's as they are generally applied in a liquid form, allowed to level, and subsequently cured. However, polyimide materials readily absorb moisture even after curing and this absorption can result in device failure. In addition, polyimides are generally not easily patterned as is often required in the manufacture of IC's and other microelectronic devices.
For optoelectronic devices, polymeric materials have been investigated as a replacement for glass optical fibers used in the manufacture of optical waveguides. Such polymeric materials are believed to hold great promise for constructing cost effective, reliable, passive and active integrated components capable of performing the required functions for integrated optics, that is to say optical devices integrated with electronic devices. For example, in U.S. Pat. No. 5,292,620, to Booth et al., waveguide structures having a predetermined geometry and a process for forming these structures using photolithographic techniques are disclosed. However, the materials disclosed in the '620 patent are acrylate type materials that have properties that are reported as making their processing difficult (see, U.S. patent application No. 20020164547 A1 to Ferm et. al.). In particular, it is disclosed that dissolved and gaseous oxygen present within or in the proximity of the photohardenable layer can quench polymerization and therefore its abundance must be carefully regulated, both within and at the immediate surface of the material. In addition, acrylate type materials, such as those of the '620 patent, are known to have relatively low glass transition temperatures which can be problematic where processing commonly used in the fabrication of microelectronic circuitry is required after waveguide fabrication.
Therefore it would be advantageous to provide polymeric materials that are useful for both microelectronic and optoelectronic devices, as well as appropriate methods for using such materials. In addition, it would be advantageous if such materials were in and of themselves photodefinable. That is to say, such materials could be patterned without the need of a distinct and separate patterning layer such as a photoresist material.